Multi-Tech Systems ISIHP-4S, ISIHP-4U Modem S-Registers, S0 Number of Rings Until Modem Answers

Modem AT Commands & S-Registers

Modem S-Registers

S-registersare small regions of memory where modem configuration information is stored. Whereas AT commands tell a modem what to do, S- registers tell the modem how to do it. Each S-register has a name that consists of the letter S and a number (S0, S1, S2, etc.), hence the term S- register. Use the Sr? command to read the value stored in an S-register and

the Sr=n command to change it.

S0 Number of Rings Until Modem Answers

Unit: 1 ring

Range: 0–255

Default: 0

Defines number of rings the modem waits before answering an incoming call. Default value is zero, which effectively disables the auto-answer function. When auto-answer is disabled, the modem can only answer via the ATA command. Set the S0 register value to one to cause the modem to answer the call immediately after the first ring. Maximum number of rings that can be configured is 255.

S1 Ring Count

Unit: 1 ring

Range: 0–255

Default: 0

Counts number of rings that have occurred. It is a read type of register and is seldom used in typical operation. Each time an incoming ring signal is detected, S1 increases its value by one, up to a maximum of 255. If you set S1 to a value other than its default value of zero, or if the value is increasing with rings, this new value remains stored in S1 for eight seconds after the last ring is counted, after which the value reverts back to zero.

S2 Escape Code Character

Unit: Decimal

Range: 0–255

Default: 43 (+)

Defines escape code character by its decimal ASCII code. Default character is the plus (+) sign (decimal 43). S2 can be set for any ASCII character.

94 MultiModemISI Hybrid Series, ISIHP-2S/2U/4S/4U/4SD